The invention concerns an apparatus for sterilising at least a segment of an inner wall and a segment of an outer wall of containers by means of accelerated charge carriers, with at least one first external application device for sterilising at least a segment of an outer wall of containers and an internal application device for sterilising at least a segment of an inner wall of containers, wherein the internal application device at least in portions can be introduced into the container through an opening in order to apply the emitted charge carriers to an internal wall of the container, with a transport device by means of which the containers can be transported along a transport path during their sterilisation.
The invention furthermore concerns a plant for treating containers which comprises at least one device for sterilising at least a segment of an inner wall and a segment of an outer wall of containers by means of accelerated charge carriers with at least one first external application device for sterilising at least a segment of an outer wall of containers and an internal application device for sterilising at least a segment of an inner wall of containers, and a method for sterilising at least a segment of an inner wall and a segment of an outer wall of containers by means of accelerated charge carriers, wherein the container is exposed to the charge carriers from at least one first external application device for sterilising at least a segment of an outer wall of containers and an internal application device for sterilising at least a segment of an inner wall of containers, wherein the internal application device at least in portions is introduced through an opening into the container in order to apply the emitted charge carriers to an inner wall of the container, wherein the containers are transported along a transport path by means of a transport device during their sterilisation.
Sterilisation of a container to be filled is, along with the actual filling process, one of the central processing steps in aseptic filling. The possible sterilisation forms vary with regard to disinfectant and process management. However, the common factor in all is that the bactericidal effect is achieved by means of chemical processes. Thus, it is known for example to sterilise the inner wall of the containers with steam or hydrogen peroxide. Such methods are however associated with disadvantages since, because of the treatment for example with hydrogen peroxide, an escape of material can occur. To prevent these disadvantages, recent developments use ionising radiation to achieve a germ reduction. This radiation in most cases comprises accelerated electrons which are generated in a corresponding plant and conducted onto or into the container to be sterilised. The result is a reduction in or complete avoidance of the use of chemical substances, and inter alia a reduction in procurement and disposal costs.
The terms “container” and “plastic container” are used synonymously below for simplicity. These terms also include pre-products of such containers. In particular these terms relate to bottles, preferably drinks bottles but also to preforms (e.g. plastic preforms for e.g. bottles). The invention can however also be applied to other containers e.g. glass bottles.
Also the terms “disinfection” and “sterilisation”, and “disinfectant” and “sterilisation agent”, are used synonymously.
A clean room is a region sealed against the environment in which conditions different from the environment in relation to sterility can be maintained. In particular a clean room is a region which fulfils specific minimum requirements in relation to maximum contamination with germs. Preferably each volume part of the clean room and each of the inner surfaces of the clean room fulfils minimum requirements in relation to sterility.
Systems for sterilisation are known from the prior art which consist of an electron generating device and a bundling device. Systems are known which sterilise containers from the outside or from the inside. In internal sterilisation, charge carriers generated outside the container to be sterilised are deflected into the container to be sterilised by various e.g. mechanical or electronic elements. In this container a cloud of electrons forms which deactivates any undesirable micro-organisms by interaction therewith.
An example of such a device for internal sterilisation of a container by means of electrons is described in DE 198 82 252 T1. An electron beam source is provided here which directs the radiation from the outside into the interior of the container.
Publication WO 97/07024 A discloses a method in which at least parts of the electron source can be introduced into the interior of the container. A method is described for cleaning or sterilising product packs by means of electron beams. The device disclosed in WO 97/07024 A comprises an electron gun which can be partially introduced into the interior of the container and carries accelerated electrons into the interior of a container. A stream of a gas introduced in parallel and interacting with the electron beam serves either to deflect the electron beam in the direction of the gas stream or as an aid to sterilisation by ionisation of the gas.
If no separate internal sterilisation of the containers is performed, significantly more powerful charge carrier generators are required as the accelerated charge carriers in addition must penetrate at least one outer wall of the container. Correspondingly strong shielding of the environment against the generated (scatter) radiation is necessary for such devices.
It would be particularly advantageous to be able to combine the benefits of internal sterilisation with those of separate sterilisation of the container outer wall. Such devices which can combine the benefits of the respective sterilisation method with those of the other method are not however known in the prior art. This is due in particular to the fact that the treatment times for the different sterilisations are different and the respective transport devices must therefore fulfil very different peripheral conditions.